how to resolve P0301 misfire code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts required.
• Ensure the vehicle is parked on a level surface with the engine off and cool.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil cover if applicable.
• Disconnect the electrical connector from the ignition coil.
• Unscrew and remove the ignition coil from cylinder 1.
• Remove the old spark plug using a spark plug socket.
• Inspect the new spark plug for proper gap and install it into cylinder 1.
• Torque the spark plug to the manufacturer's specifications (usually around 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel injector removal tool, socket set, torque wrench.
• Relieve fuel system pressure using the service manual instructions.
• Disconnect the injector connector and fuel line from the injector.
• Remove the retaining clips and extract the fuel injector from the intake manifold.
• Install the new fuel injector, ensuring proper alignment.
• Reconnect the fuel line and electrical connector, ensuring all clips are secure.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear the P0301 code.
• Start the engine and monitor for any reoccurrence of the check engine light.